Methods and apparatus for stabilizing a spinal segment

ABSTRACT

One or more sutures can be used in spinal applications to hold an intradiscal device in place between two vertebrae or repair a defect in the soft tissue of the spine, such as the annulus fibrosis or the dura. Tension can also be applied to the sutures to stabilize a spinal segment having an intradiscal device to prevent or minimize excessive spinal extension, lateral bending, and axial rotation of the spinal segment. Anchors are placed in two adjacent vertebrae and sutures are passed through each anchor. The sutures can be passed through portions of the intradiscal device. Alternatively, the sutures can be passed through a mesh patch which is held against the vertebrae to hold the intradiscal device in place. Tension is applied to the first and second ends of the sutures and the sutures are welded together. The sutures can be welded in a cross-braced arrangement minimize or prevent extension, lateral bending, and rotation of the spinal segment. For example, the sutures can be welded in a diagonal pattern, a horizontal pattern, a vertical pattern or any combination thereof across the adjacent vertebrae.

RELATED APPLICATIONS

This application claims the benefit of provisional application60/861,499, filed Nov. 28, 2006, entitled “Annulus and Spinal LigamentReconstruction,” This application is related to co-pending application60/808,795, filed May 26, 2006, entitled “Fastening Assemblies for DiscHerniation Repair and Methods of Use.” The application is also relatedto U.S. Pat. Nos. 6,248,106 and 6,423,065. All of the above-referencedpatent and applications are hereby expressly incorporated by referencein their entirety.

FIELD OF THE INVENTION

The subject invention resides in methods and apparatus forreconstructing the annulus fibrosis (AF) of a spinal disc and theligaments of the spine. The invention is particularly well suited to therepair of defects in the annulus fibrosis and prevention of extrusion ofmaterial or devices placed into the disc space and to the prevention ofexcessive spinal motion.

BACKGROUND

The human intervertebral disc is an oval to kidney bean-shaped structureof variable size depending on the location in the spine. The outerportion of the disc is known as the annulus fibrosis (AF). The annulusfibrosis is formed of approximately 10 to 60 fibrous bands or layers.The fibers in the bands alternate their direction of orientation byabout 30 degrees between each band. The orientation serves to controlvertebral motion (one half of the bands tighten to check motion when thevertebra above or below the disc are turned in either direction).

The annulus fibrosis contains the nucleus pulposus (NP). The nucleuspulposus serves to transmit and dampen axial loads. A high water content(approximately 70-80%) assists the nucleus in this function. The watercontent has a diurnal variation. The nucleus imbibes water while aperson lies recumbent. Nuclear material removed from the body and placedinto water will imbibe water swelling to several times its normal size.Activity squeezes fluid from the disc. The nucleus comprises roughly 50%of the entire disc. The nucleus contains cells (chondrocytes andfibrocytes) and proteoglycans (chondroitin sulfate and keratin sulfate).The cell density in the nucleus is on the order of 4,000 cells permicroliter.

The intervertebral disc changes or “degenerates” with age. As a personages, the water content of the disc falls from approximately 85% atbirth to approximately 70% in the elderly. The ratio of chondroitinsulfate to keratin sulfate decreases with age, while the ratio ofchondroitin 6 sulfate to chondroitin 4 sulfate increases with age. Thedistinction between the annulus and the nucleus decreases with age.Generally disc degeneration is painless.

Premature or accelerated disc degeneration is known as degenerative discdisease. A large portion of patients suffering from chronic low backpain are thought to have this condition. As the disc degenerates, thenucleus and annulus functions are compromised. The nucleus becomesthinner and less able to handle compression loads. The annulus fibersbecome redundant as the nucleus shrinks. The redundant annular fibersare less effective in controlling vertebral motion. This disc pathologycan result in: 1) bulging of the annulus into the spinal cord or nerves;2) narrowing of the space between the vertebra where the nerves exit; 3)tears of the annulus as abnormal loads are transmitted to the annulusand the annulus is subjected to excessive motion between vertebra; and4) disc herniation or extrusion of the nucleus through complete annulartears.

Current surgical treatments for disc degeneration are destructive. Onegroup of procedures, which includes lumbar discectomy, removes thenucleus or a portion of the nucleus. A second group of proceduresdestroy nuclear material. This group includes Chymopapin (an enzyme)injection, laser discectomy, and thermal therapy (heat treatment todenature proteins). The first two groups of procedures compromise thetreated disc. A third group, which includes spinal fusion procedures,either remove the disc or the disc's function by connecting two or morevertebra together with bone. Fusion procedures transmit additionalstress to the adjacent discs, which results in premature discdegeneration of the adjacent discs. These destructive procedures lead toacceleration of disc degeneration.

Prosthetic disc replacement offers many advantages. The prosthetic discattempts to eliminate a patient's pain while preserving the disc'sfunction. Current prosthetic disc implants either replace the nucleus orreplace both the nucleus and the annulus. Both types of currentprocedures remove the degenerated disc component to allow room for theprosthetic component. Although the use of resilient materials has beenproposed, the need remains for further improvements in the way in whichprosthetic components are incorporated into the disc space to ensurestrength and longevity. Such improvements are necessary, since theprosthesis may be subjected to 100,000,000 compression cycles over thelife of the implant.

Current nucleus replacements (NRs) may cause lower back pain if too muchpressure is applied to the annulus fibrosis. As discussed in co-pendingU.S. patent application Ser. No. 10/407,554 and U.S. Pat. No. 6,878,167,the content of each being expressly incorporated herein by reference intheir entirety, the posterior portion of the annulus fibrosis hasabundant pain fibers.

Herniated nucleus pulposus (HNP) occurs from tears in the annulusfibrosis. The herniated nucleus pulposus often allies pressure on thenerves or spinal cord. Compressed nerves cause back and leg or arm pain.Although a patients symptoms result primarily from pressure by thenucleus pulposus, the primary pathology lies in the annulus fibrosis.

Surgery for herniated nucleus pulposus, known as microlumbar discectomy(MLD), only addresses the nucleus pulposus. The opening in the annulusfibrosis is enlarged during surgery, further weakening the annulusfibrosis. Surgeons also remove generous amounts of the nucleus pulposusto reduce the risk of extruding additional pieces of nucleus pulposusthrough the defect in the annulus fibrosis. Although microlumbardiscectomy decreases or eliminates a patient's leg or arm pain, theprocedure damages weakened discs.

Suture anchor and knotless suture fastening technology have been usedextensively to repair soft tissues about the knee and shoulder. Thesutures are used to attach the soft tissues to the bones that form thejoints. The anchor is embedded in the bone. The ends of the suture arethen passed through the tendon, such as the rotator cuff of the shoulderand fastened to one another. Recessing the suture welds in the softtissue over the bone prevents friction between the suture and the boneand prevents the ends of the sutures from catching on adjacent tissuesand thus peeling the weld apart.

Suture anchors eliminate the laborious method of threading suturesthrough holes drilled into bones. The use of a weld is better than theuse of knots in the prior art because knots are difficult to tie duringarthroscopic procedures and slip several millimeters allowing the softtissues within the suture to migrate away from the bone. However, suchtechnology has rarely been used for reconstructive spinal procedures.Suture based spinal devices would be exposed to substantially higherloads, more friction, and must work longer than such devices are exposedto in the shoulder. In spinal applications, the sutures, including thewelded portion of the sutures would lie directly against the vertebraeof the spinal device and thus would be subjected to more friction thansutures and welds of a device connecting bone and soft tissue. Moreover,the high profile of the sutures and especially the suture welds notrecessed within soft tissue would increase the excessive wear on thesutures and the risk of peeling the suture welds apart.

SUMMARY

During insertion of an intradiscal device, a portion of the annulusfibrosis and a portion of the ligaments of the spine are excised toallow insertion of materials and devices into the disc space. Forexample, a portion of the anterior half of the annulus fibrosis and aportion of the anterior longitudinal ligament (ALL) are excised toenable insertion of bone growth promoting materials and fusion devicesin interbody fusion procedures. A portion of the annulus fibrosis and aportion of the anterior longitudinal ligament are also excised to enableinsertion of motion preserving devices into the disc. For example, TotalDisc Replacements (TDRs) and Nucleus Replacements (NRs) are ofteninserted through the anterior portion of discs.

Removal of portions of the annulus fibrosis and anterior longitudinalligament increase the flexibility of the spine and allow excessivemotion of the spine. For example, removal of the tissues mentionedpermits excessive spinal extension, lateral bending, and axial rotation.Destabilizing the spine decreases the chance of a successful fusion foran interbody fusion procedure. Destabilizing the spine followingexcision of the spinal tissues and insertion of motion preservingdevices into the disc space places excessive force on the facets of thespine. Biomechanical studies show the forces across the facets at theoperated level of the spine can be doubled by motion preserving devicesand the techniques used to insert such devices. Excessive force on thefacets may lead to degeneration of the facets. Degeneration of thefacets may cause low back pain.

The present invention provides methods for using sutures in spinalapplications to stabilize a spinal segment and/or hold an intradiscaldevice in place without passing the sutures through soft tissue. Theinvention can be used to prevent or minimize excessive spinal extension,lateral bending, and axial rotation.

In one embodiment, anchors are placed in two adjacent vertebrae andsutures are passed through each anchor. The first end of one sutureextending from the anchor in the cranial vertebra is welded to the firstend of a second suture extending from the anchor in the caudalvertebrae. Tension is applied to second ends of the first and secondsutures and the second ends are welded together.

In some embodiments, two or more anchors can be used in each vertebraeand the sutures may be welded in a cross-braced arrangement minimize orprevent extension, lateral bending, and rotation of the spinal segment.For example, the sutures can be welded in a diagonal pattern, ahorizontal pattern, a vertical pattern or any combination thereof acrossthe adjacent vertebrae. Tension can be applied across the sutures priorto welding to provide compression across the disc space between theadjacent vertebrae. In other embodiments, two or more sutures may bethreaded through each anchor to provide additional tension andcompression across the spinal segment.

In some embodiments, a mesh patch can be placed between the sutures andthe vertebrae to provide a cushion between the sutures and the bone andreduce friction on the sutures and the suture welds. In someembodiments, the material for the mesh can be selected such thatconnective tissue will grow into and over the mesh in vivo, forming asynthetic tendon-like layer that further cushions and protects thesutures. In some embodiments, an anti-adhesion patch can be placed overthe exposed portions if the sutures and the suture anchors to protectthe suture welds from friction with adjacent structures that couldcreate peeling forces and pull the suture welds apart as well as toprotect the adjacent structures from the stiff ends of the suture welds.

The invention may also be used to tether the spine. Tethering theimmature spine enables correction of spinal deformities as the spinegrows. The invention may incorporate materials that encourage the growthof connective tissue into components of the various devices taught inthe invention. The invention may also incorporate materials that preventthe growth of connective tissue into components of the various devicestaught in the invention. Preventing or limiting connective in-growth maybe used to diminish adhesions at the surgical site.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an anterior view of segment of a spine with sutureanchors placed in adjacent vertebrae and first ends of sutures extendingfrom each anchor welded together.

FIG. 1B illustrates an anterior view of the embodiment in FIG. 1A withsecond ends of the sutures welded together.

FIG. 2A illustrates an anterior view of an alternative embodiment havingsutures placed in adjacent vertebrae and two sutures extending from eachanchor.

FIG. 2B illustrates an anterior view of the embodiment in FIG. 2A withthe sutures welded together in a cross-braced pattern.

FIG. 2C illustrates an anterior view of the embodiment in FIG. 2B withan anti-adhesion cover placed over the fixation sutures and sutureanchors.

FIG. 2D illustrates an anterior view of the embodiment in FIG. 2C withan anti-adhesion cover sutured over the fixation sutures and sutureanchors.

FIG. 2E is an anterior view of a portion of the lumbosacral spine, aportion of the aorta, a portion of the vena cava, portions of the iliacarteries portions of the iliac veins 36, and the embodiment of theinvention drawn in FIG. 2D.

FIG. 2F is a lateral view of the spine and the embodiment of theinvention drawn in FIG. 2E.

FIG. 2G is a lateral view of a sagittal cross section of the spine andthe embodiment of the invention drawn in FIG. 2F

FIG. 2H illustrates an anterior view of the spine and an alternateembodiment of the invention drawn in FIG. 2D.

FIG. 3A illustrates is a lateral view of the spine and an alternativeembodiment of the invention drawn in FIG. 2D placed on the lateralportion of the vertebrae.

FIG. 3B illustrates an anterior view of the embodiment in FIG. 3A.

FIG. 4A illustrates an anterior view of an alternative embodiment of theinvention wherein one or more sutures can be used to tether the spine.

FIG. 4B is a lateral view of the spine and the embodiment of theinvention drawn in FIG. 4A.

FIG. 4C is lateral view of the spine and an alternative embodiment ofthe invention drawn in FIG. 4B.

FIG. 5 is a lateral view of a portion of the spine and an alternativeembodiment of the invention drawn in FIG. 4A wherein the sutures areplaced on the posterior portion of the spine.

FIG. 6A is a posterior view of the spine illustrating an alternativeembodiment of the invention for tethering the spine wherein the suturesare passed under the lamina of the vertebrae.

FIG. 6B is a posterior view of the embodiment in FIG. 5. The ends ofsutures 6 showing the sutures welded together around a spinal rod.

FIG. 7A is a posterior view of the cervical spine illustrating anembodiment of the invention in portions of the cervical spine.

FIG. 7B is a posterior view of the cervical spine illustrating analternative embodiment of the invention in portions of the cervicalspine.

FIG. 8A is a posterior view of the cervical spine illustrating analternative embodiment of the invention in portions of the cervicalspine.

FIG. 8B is a posterior view of the embodiment in FIG. 5A showing thesutures welded together over bone graft material.

FIG. 9A illustrates an alternative embodiment of the invention using oneor more sutures to attach prosthetic devices to the spine.

FIG. 9B is an anterior view of a portion of the embodiment of theinvention drawn in FIG. 9A showing the sutures welded together over theprosthetic device.

FIG. 9C is an anterior view of a portion of the embodiment of theinvention drawn in FIG. 9B showing an anti-adhesion cover placed overthe suture welds.

FIG. 10A illustrates an alternative embodiment of the invention usingone or more sutures to hold an intradiscal device in the disc spacebetween two vertebrae.

FIG. 10B is an anterior view of a portion o the embodiment of theinvention drawn in FIG. 10A showing an anti-adhesion cover placed overthe suture welds.

FIG. 11A is a posterior view of a coronal cross section of the spinethrough the pedicles of the vertebrae illustrating a defective region inthe annulus fibrosis.

FIG. 11B illustrates an embodiment of method of using sutures to closethe defect in the annulus fibrosis of FIG. 10A

FIG. 12A is a posterior view of a portion of the dura. The dura has anincision, tear, or laceration.

FIG. 12B illustrates an embodiment of a method of using one or moresutures to close a defect in the spinal dura.

DETAILED DESCRIPTION

FIGS. 1A-1B illustrate a method using two sutures to join adjacentvertebrae. Anchors 10 a and 10 b are placed in vertebrae 100 and 102respectively. Suture 6 a is threaded through anchor 10 a and suture 6 bis threaded through anchor 10 b. The sutures 6 a and 6 b are made ofmaterials than can be welded together. For example, the sutures can bemonofilament or multifilament configurations of nylon, polypropylene,polyester, polyethylene, or other suitable material. The sutures 6 a and6 b can be different sizes and/or made of different materials

As shown in FIG. 1A, the first end of one suture 6 a is welded to thefirst end of a second suture 6 b to form a suture weld 7. The weld ispreferably caused by heat-generating or heat-conducting instruments. Theheat may be generated ultrasonically or by other means. Next, as shownin FIG. 2B, the second ends of the two sutures 6 a and 6 b are weldedtogether to form suture weld 9. During welding of the second ends of thesutures 6 a, 6 b, care must be taken so that the first weld 7 is notadvanced into an eyelet of anchor 10 a or 10 b, which could result inpeeling apart of the weld 7. In order to prevent the weld 7 fromimpinging on anchor 10 a or 10 b, equal tension is applied to both endsof sutures 6 a, 6 b. In addition, in some embodiments, both ends of thesutures can be advanced through the eyelets of the anchors, in oppositedirections, to prevent impingement of a prior weld against a sutureanchor. For example, after the first weld 7, if both sutures 6 a,btravel through the eyelets of the anchors 10 a,b in the same direction,for example clockwise, the first weld may impinge on an anchor. However,if the first suture 6 a is pulled through anchor 10 a in a clockwisedirection and the second suture 6 b is pulled through anchor 10 b thesame distance but in a counterclockwise direction, the first weldremains positioned between the anchors 10 a,b rather than possiblyimpinging against an anchor.

In some embodiments, the sutures may be used to stabilize a spinalsegment after a portion of the annulus fibrosis and/or a portion of theligaments of the spine have been excised during insertion of anintradiscal device. FIG. 2A is an anterior view of the spine, a totaldisc replacement (TDR), and four suture anchors. The anterior portion ofthe annulus fibrosis II and the anterior longitudinal ligament 13 wereexcised to permit insertion of the total disc replacement (TDR) 15 intothe disc space. Two suture anchors 10 a, 10 b were placed into thevertebra 100 cranial to the disc and two suture anchors 10 c, 10 d wereplaced into the vertebra 102 caudal to the disc. Each suture anchor 10a,b,c,d has two eyelets with first sutures 6 a,b,c,d and an secondsutures 8 a,b,c,d passing therethrough.

As discussed above, the sutures 6 a,b,c,d and 8 a,b,c,d are made ofmaterials than can be welded together. For example, the sutures can bemonofilament or multifilament configurations of nylon, polypropylene,polyester, polyethylene, or other suitable material. In someembodiments, the first set of sutures 6 a,b,c,d and the second set ofsutures 8,a,b,c,d could be different sizes and/or made of differentmaterials. For example, one set of sutures 6 a-d could be a #5 polyestermultifilament material. The other set of sutures 8 a-d could be made ofa #5 resorbable multifilament suture, such as Vicryl (Ethicon, N.J.).Alternatively, one set of sutures could be more elastic than the secondset of sutures. For example, one set of sutures 6 a-d could reversiblystretch about 1 to about 10 mm. The other set of sutures 8 a-d couldreversibly stretch about 5 to about 8 mm. Embodiments of the inventionused in spinal fusion procedures preferably include relatively inelasticsutures.

In addition, in different embodiments, the anchors could vary in sizefrom about 3 to about 12 mm in diameter and about 4 to about 40 mm inlength. For example, anchors having a diameter of about 3 mm and alength of about 7 mm could be used in the anterior portions of cervicalvertebrae. Additionally, anchors having a diameter of about 8 mm and alength of about 35 mm could be used in the anterior portions of lumbervertebrae. The anchors are preferably made of a MRI-compatible material.For example, the anchors could be made of titanium, plastic, or othermaterial. The anchors may additionally be coated with a material, suchas hydroxyappetite, that promotes the in-growth of bone. In analternative embodiment, the anchors could be hollow and filled with amaterial that promotes bone in-growth.

With reference to FIG. 2B, the medial ends of the sutures 6 a-d and 8a-d from the anchors are welded together in a diagonal pattern over thedisc space. The lateral ends of one set of sutures 6 a-d are then weldedtogether to create vertical fixation suture arms and the lateral ends ofthe second set of sutures 8 a-d are welded together to create horizontalfixation suture arms. Tension is applied to the sutures 6 a,b,c,d and8,a,b,c,d before the sutures 6 a,b,c,d and 8,a,b,c,d are weldedtogether. As discussed above, during subsequent welds, equal tension isapplied to both ends of the sutures having a preceding suture weld toensure that preceding suture welds are not advanced into the eyelet ofanchor 10 a,b,c,d which could result in peeling apart of the weld.

In an alternative embodiment, both sets of the lateral ends of thefixation sutures could have been welded to create two sets of verticalfixation suture arms (not shown). In general, the sutures can be weldedin a pattern having any combination of diagonal connections, generallyupper and lower horizontal connections, and/or generally left and rightvertically extending connections. For example, in some embodiments, thesutures may be welded in a pattern of a FIG. 8 having both generallyvertically extending fixation suture arms and diagonal fixation suturearms. In alternative embodiments, the sutures may be welded in a patternof a quadrilateral, having generally horizontal and vertical suturearms, with diagonal suture arms extending between the vertices.

The weld is preferably caused by heat-generating or heat-conductinginstruments. The heat may be generated ultrasonically or by other means.Instruments with special tips may be used to weld the sutures withindeep areas of the body. For example, instruments that are about 15 toabut 45 cm in length may be needed to weld sutures in the abdomen. Thewelding instruments are preferably about 4 to about 8 mm in diameter.

In some embodiments, a piece of porous mesh material 16 is placedbetween the fixation sutures 6 a-d, 8 a-d and the vertebrae 100, 102.The mesh 16 acts as scaffolding for connective tissue in-growth from theannulus fibrosis 1, the anterior longitudinal ligament 13, and thevertebrae 100, 102. The mesh between the sutures 6 a,b,c,d and 8 a,b,c,dand the vertebrae 100 and 102, forms a synthetic tendon-like layer thatcushions and protects the sutures 6 a,b,c,d and 8 a,b,c,d, andespecially the suture welds, from damage due to the motion between thesutures 6 a,b,c,d and 8 a,b,c,d and the vertebrae 100 and 102. The poreswithin the mesh 16 are preferably about 0.1 to 2.0 mm in diameter. Meshpiece 16 may be made of synthetic materials such as polyester,polypropylene, ePTFE, or polyethylene. Alternatively, the mesh could bemade of natural material such as autograft, allograft, or xenografttissues such as acellular dermis, swine intestinal submucosa, ligaments,facia, or tendon. The mesh 16 should extend over both sides of theanterior longitudinal ligament 13 and the annulus fibrosis 11 on eitherside of the annular window. The connective tissue, the mesh 11, and thefixation sutures 6 a,b,c,d and 8 a,b,c,d at least partially reproducethe function of the annulus fibrosis and the anterior longitudinalligament. The components also prevent extrusion of tissue that resideswithin the disc, such as the nucleus pulposus, or materials or devicesthat are placed within the disc. Radio-opaque markers could be added tothe mesh and or the fixation sutures to help identify the location ofthe components on x-ray. For example, metal wires or staples could beincluded in mesh or fixation sutures. Alternatively, radio-opaquematerials such as barium or other contrast agents may be used to “dye”the mesh or fixation sutures.

In some embodiments, the sutures and anchors can be covered with ananti-adhesion component as described in patent application 60/808,795,filed May 26, 2006, entitled “Fastening Assemblies for Disc HerniationRepair and Methods of Use,” hereby expressly incorporated by referencein its entirety. For example, as shown in FIG. 2C, two connectingsutures 22 and 24 can be used to connect the anti-adhesion patch 20 tomesh patch 16. The connecting sutures 22 and 24 are passed through meshpatch 16 and anti-adhesion cover 20 and then joined together, forexample by welding or any other suitable method, over the anti-adhesioncover 20 to hold the anti-adhesion cover against the vertebrae 100, 102and annulus fibrosis 11. As shown in FIG. 2D, anti-adhesion cover 20 issized to extend over the anchors 10 a-d, mesh 16, fixation sutures 6a,b,c,d and 8 a,b,c,d, the cut edges of the annulus fibrosis 111, andthe cut edges of the anterior longitudinal ligament 113. In analternative embodiment, as shown in FIG. 2H, a single connecting suture22 can be passed through the mesh patch and anti-adhesion cover 20 andthen welded, or otherwise joined, together to hold the anti-adhesioncover 20 against the vertebrae 100, 102 and annulus fibrosis 11.

Placing the stiff ends of the sutures beneath the anti-adhesion patch 20further protects the suture welds from peeling forces due to frictionfrom adjacent structures and helps prevent injury to delicate structuressuch as nerves, blood vessels, and the esophagus that lie directly overthe stiff ends of the sutures. For example, as shown in FIGS. 2E-G, inan embodiment placed in the lumbrosacral spine, anti-adhesion component20 lies between the incised portion of the spine, including the exposedportions of the suture anchors 10 a,c and sutures 6 a,c and 8 a,c andthe mesh patch 16, and the great vessels, including a portion of theaorta 30, a portion of the vena cava 32, portions of the iliac arteries34, portions of the iliac veins 36. In some embodiments, theanti-adhesion component 20 further covers a portion of annulus fibrosis11 and upper and lower vertebrae 100, 102. Welded sutures 22, 24 on theanterior side of anti-adhesion cover 20, holding anti-adhesion cover 20against annulus fibrosis 11. The sutures 22, 24 that hold theanti-adhesion cover 20 against the annulus fibrosis 11 are more flexibleand have a smaller diameter than the fixation sutures therefore peelingforces or injury to the adjacent structures is not an issue. Similarly,in cervical embodiments of the invention, the anti-adhesion componentlies between the exposed portions of the suture anchors and sutures andthe esophagus. In some embodiments, the anti-adhesion component 20 canextend further over the adjacent discs of the spine.

The anti-adhesion cover could be a piece of ePTFE attached to a portionof the mesh device and/or the fixation sutures. The anti-adhesion covercould also be made of Sepratfilm autograft, allograft, or xenografttissues such as acellular dermis, swine intestinal submucosa, ligaments,facia, or tendon. Alternatively, the device may include a singlecomponent made of autograft, allograft, or xenograft tissues such asacellular dermis, swine intestinal submucosa, ligaments, facia, ortendon. The anti-adhesion cover may be attached to a portion of the meshpatch or device in a contracted configuration, where the anti-adhesioncomponent is capable of being opened into an expanded configuration. Theanti-adhesion component may be attached to a center portion of the meshpatch or at least one edge of the mesh patch. In the contractedconfiguration, the anti-adhesion cover may be bunched together, rolled,or gathered. The anti-adhesion component may be held in the contractedconfiguration by one or more sutures constraining element.

The invention may be used on the anterior, lateral, or posteriorportions of the cervical, thoracic, lumbar, or sacral regions of thespine. For example, in an alternative embodiment, as shown in FIGS.3A-B, the device can be placed over the lateral aspect of the spine. Forexample, the suture anchors 10 a,b are inserted into the lateral portionof upper and lower vertebra 100 and 102 and sutures are passed throughsuture anchors 10 a,b and 10 c,d (not shown) and arranged over anannular window in the lateral portion of the annulus fibrosis 11. Anintradiscal device 105, such as a nucleus replacement (NR), bone graft,spinal cage, or TDR can be inserted into the disc space betweenvertebrae 100 and 102. Sutures extending from suture anchors 10,a,b,c,dare then welded together over the intradiscal space in a patterndescribed above in reference to FIG. 2B. Tension can be applied to thesutures prior to welding together so that the sutures apply compressionto vertebrae 100, 102 as well as hold the intradiscal device 105 inplace between the vertebrae 100, 102. A mesh patch 16 is placed betweenthe annulus fibrosis 11 and the suture welds. A second set of sutures22, 24 are threaded through mesh patch 16 and anti-adhesion cover 20 andwelded together over the anterior side of anti-adhesion cover 20 to holdanti-adhesion cover 20 against mesh patch 16, which is adjacent annulusfibrosis 11.

In some embodiments, as shown in FIG. 4A-C, one or more sutures can beused to tether the spine. Tethering the immature spine enablescorrection of spinal deformities such as scoliosis as the spine grows.The drawings illustrate the coronal plane deformity of scoliosis.Anchors 10 e-j were placed into the lateral portions of the vertebrae onthe convex side 141 of the curve. In alternative embodiments of theinvention, anchors 10 e-j could extend through the vertebrae. A singlesuture, or multiple sutures, may be threaded through the head of theanchor. Sutures 6 e-j from the anchors 10 e-j are welded together overthe convex portion of the curve, thus allowing more growth of theportions of the vertebrae on the concave side of the spine than of theportions of the vertebrae on the convex side of the spine. The treatedspine straightens as it grows. The sutures can be cut at a later surgeryto prevent over correction of the spine and to allow movement across thediscs.

In one embodiment, as shown in FIG. 4B, the ends of the sutures arewelded together over the apex of the curve in the spine. Sutures 46 afrom anchors 10 g, 10 h in the vertebrae in the center of the curve lieover a single disc while the sutures 46 e,f from the anchors 10 e,j inthe vertebrae at the ends of the curve pass over five discs. Tension isapplied to the fixation sutures before welding the sutures together.Porous mesh sleeves (not shown) may be placed over the welded sleeves.The sleeves may be contracted, like an accordion, to facilitate weldingof the sutures. The sleeves may be expanded over the sutures afterwelding the ends of the sutures. Additionally, the mesh sleeves andfixation sutures may be covered with an anti-adhesion component (notshown). The anchors 10 e-j may be placed near the anterior portions ofthe vertebrae to increase kyphosis of the spine with growth of theimmature spine.

In an alternative embodiment, as shown in FIG. 4C sutures 56 e-l fromadjacent anchors 10 e-l are welded to each other, i.e., suture 56 e waswelded to suture 56 f and suture 56 g was welded to suture 56 h. Theembodiment of the invention helps correct rotational deformities of thespine. As described with respect to FIG. 4B, the sutures may besurrounded by mesh sleeves (not shown). Alternatively, as described inrespect to FIG. 2B, porous mesh (not shown) could be placed between thewelded sutures and the spine. In some embodiments, the fixation sutures,anchors, and mesh components could be covered with an anti-adhesioncomponent or anti-adhesion components.

FIG. 5 is a lateral view of a portion of the spine and an alternativeembodiment of the invention drawn in FIG. 4A. The sutures 6 a-d from theanchors 10 a-d were welded over the posterior portion of the spine. Theanchors 10 a-d were placed into the posterior portions of the vertebrae100,102,104,106. The invention may be applied to immature spines withexcessive kyphosis. The posterior tether allows the spine to straightenas the spine grows.

FIG. 6A is a posterior view of the spine and an alternative embodimentof the invention. The spine was drawn with scoliosis. Sutures 6 b-j werepassed under the lamina of the vertebrae 100, 102, 104, 106 and 108.Sutures 6 a-j were also passed around a spinal rod 33. Alternatively,the sutures 6 b-could have been passed around the transverse processesof the vertebrae. Alternatively, sutures could extend from anchorsplaced into the posterior portions of the vertebrae or ribs.

FIG. 6B is a posterior view of the spine and the embodiment of theinvention drawn in FIG. 5A. The ends of sutures 6 a-j were weldedtogether around spinal rod 33 after applying tension to the ends of thesutures 6 a-j. The embodiment of the invention could be used in spinalfusion and in fusion-less scoliosis procedures.

As discussed above, the some embodiments can be used on the anterior,lateral, or posterior portions of the cervical spine. For example, asshown in FIG. 7A suture 66 can be wrapped around the posterior portionof C1 vertebra and around the spinous process 60 of the C2 vertebra. Theends of suture 66 can then be welded together after applying tension tothe ends of the suture. The embodiment may be used in C1-C2 fusionprocedures. Similar procedures using the welded sutures can be performedon other vertebrae. For example as shown in FIG. 7B, two sutures 6, 8can be placed under the lamina of C2 vertebra and the posterior portionof the C1 vertebra. The sutures 6, 8 can then be welded together afterapplying tension to the ends of the sutures 6,8. The embodiment of theinvention may be used in C1-C2 fusion procedures, and the fusion ofother vertebrae. Alternatively, as shown in FIGS. 8A-B, sutures 6 and 8can be wrapped around and through the spinous processes 60, 62 of twocervical vertebrae and through two pieces of bone graft material 37. Thesutures 6, 8 can then be welded together after applying tension to theends of the sutures 6,8.

In some embodiments, one or more sutures can be used to hold anintradiscal device in the disc space and/or to attach prosthetic devicesto the spine. For example, as shown in FIG. 9A, anchors 10 a,b,c,d areplaced in two adjacent vertebrae 100, 102. Sutures 6 a,b,c,d arethreaded through anchors 10 a,b,c,d respectively. The sutures 6 a,b,c,dare then passed through portions of a disc replacement device 40, forexample in one embodiment the sutures 6 a,b,c,d could be passed throughthe polyester portion of the Neodisc (NuVasive, San Diego Calif.). Thedisc replacement device 4U is placed in the disc space 103 betweenvertebrae 100, 102. Tension is applied to sutures 6 a,b,c,d and thesutures 6 a,b,c,d are welded together. In some embodiments the suturesmay be used to hold the disc replacement device in place in disc space103. In alternative embodiments, the sutures 6 a,b,c,d can also be usedto apply compression to the vertebrae 100, 102. The arrangement of thewelded sutures and the tension applied to the sutures prior to weldingcan be varied depending on the disc replacement device used and thefunction of the sutures 6 a,b,c,d, i.e. whether the sutures are used tohold the disc replacement device in place or additionally to providestabilization to the spine. For example, as shown in FIG. 9B, thesutures 6 a and b can be welded together to form a first horizontalsuture arm and the sutures 6 c and d can be welded together to form asecond horizontal suture arm to attach the intradiscal device 40 to thevertebrae 100 and 102. In an alternative embodiment, the sutures 6a,b,c,d can be welded together in an arrangement as discussed above inrespect to FIG. 2B to form vertical or diagonal suture arms for holdingthe device 40 in the interdiscal space and for stabilizing the portionof the spine where the annulus fibrosis was excised in order to placethe intradiscal device 40.

In some embodiments, as shown in FIG. 9C, an anti-adhesion component 20can be attached to the anterior portion of the prosthetic device 40.Sutures 22, 24 can be threaded through the intradiscal device 40 and theanti-adhesion patch 20 then welded together to attach the anti-adhesionpatch to the intradiscal device 40. As discussed above, theanti-adhesion component 20 prevents adhesions between the device 40 andthe surrounding soft tissues. For example, anti-adhesion component 20could be added to the disc replacement device 40, such as the Neodiscdevice, to prevent adhesions between the device 40 and delicatestructures such as nerves, blood vessels, and the esophagus.

In an alternative embodiment, the sutures 6 a,b,c,d can be used inconjunction with an anti-adhesion patch 20 to hold an intradiscal device90 in place between two adjacent vertebrae 100, 102. As shown in FIG.10A, an intradiscal device or bone graft 90 is placed between vertebrae100, 102. Anchors 10 a,b,c,d are inserted into vertebrae 100,102 andsutures 6 a,b,c,d are threaded through anchors 10 a,b,c,d. Sutures 6a,b,c,d are then threaded through anti-adhesion cover 20. As shown inFIG. 10B, anti-adhesion cover is positioned over vertebra 100,102 andattached to the spine with sutures 6 a,b,c,d. Sutures 6 a and 6 b arewelded to form a first horizontal suture arm and sutures 6 e and d arewelded together to form a second horizontal suture arm. Tension isapplied to sutures 6 a,b,c,d prior to welding to hold anti-adhesioncover 20 against the vertebrae 100, 102, thereby holding intradiscaldevice 90 in place in between vertebrae 100, 102. In some embodiments,as discussed above additional tension is applied to the sutures 6a,b,c,d to provide stabilization for the portion of the spine where theannulus fibrosis was excised in order to place the intradiscal device90.

In some embodiments, one or more sutures can be used to repair or closedefects in the soft tissue surrounding the spine such as the dura orannulus fibrosis. For example, at times the rotational, translational,and axial compression forces exceed the strength of the annular fibersresulting in tears in the annular fibers. A single event can tear oneband to all the bands. Subsequent tears can connect to previous tears ofa few bands resulting in a hole 120 through the entire annulus fibrosis11 as shown in FIG. 11A. Holes through the entire annulus fibrosis canresult in extrusion of the nucleus pulpous. Extrusion of the nucleuspulpous is referred to as a “herniated disc.” Disc herniation can resultin back pan, neck pain, arm pain, leg pain, nerve or spinal cord injury,or a combination of the above. With reference to FIG. 11B, sutures 6a,b, each having first and second ends, are placed across the defectiveregion 120 of the annulus fibrosis 11 and first and second ends arepassed through the annulus fibrosis 11 above and below the defectiveregion 120. The sutures are preferably oriented perpendicular to thedefect in the annulus. The sutures are preferably passed through theannulus and into a lumen within the tool, thus keeping the tips of theneedles from injuring the nerves. For example, suture passing andwelding tools from Axya Medical (Beverly, Mass.) could be used in thisembodiment of the invention. Tension is applied to the sutures 6 a,b topull the defective region 120 closed and the first and second ends ofeach suture 6 a,b are welded together. This embodiment can be used toprevent materials from leaking from the disc through the annulusfibrosis 11. For example, the invention could be used to prevent thenucleus pulpous from extruding from the disc. The invention could alsobe used to prevent materials that were placed into the disc from leakingout of the disc.

With reference to FIGS. 12A-B, some embodiments can be used to close adefect in the spinal dura. As shown in FIG. 12A, the dura 15 has anincision, tear, or laceration 130. As shown in FIG. 12B, sutures 6 a,bare threaded through the dura 15 across the defect 130. Tension isapplied to the first and second ends of the suture 6 a,b and the firstand second ends of each suture are welded together. In the illustratedembodiment, two sutures 6 a,b are used to close the defect in the dura.In alternative embodiments, depending on the size of the tear, more orless sutures can be used to close the defect. For example, for a smalltear in the dura, one suture may be adequate to repair the defect.However, if the tear is large or long, three, four or more sutures maybe needed to close the tear in the dura. Welding the sutures istechnically easier that tying knots in the sutures. The sutures can alsobe welded through smaller incisions than sutures can be tied through.Welding sutures have a lower profile than tied sutures. Lastly welds arestronger, more consistent, and less likely to allow the suture loop tolengthen than tied sutures.

Although the foregoing invention has, for the purposes of clarity andunderstanding, been described in some detail by way of illustration andexample, it will be obvious that certain changes and modifications maybe practiced which will still fall within the scope of the appendedclaims.

1. A method for stabilizing a spinal segment, comprising the steps of:providing first, second, third, and fourth anchors, wherein each anchorcarries a first elongate cable having first and second ends that extendfrom each anchor and a second elongate cable having first and secondends that extend from each anchor; attaching the first anchor to a firstvertebra, attaching the second anchor to the first vertebra, attachingthe third anchor to a second vertebra, and attaching the fourth anchorto the second vertebra; and attaching each of the first and second endsof the first and second elongate cables of the first anchor to create anattachment with one of the first and second ends of one of the first orsecond elongate cables of the second, third, and fourth anchors,attaching each of the first and second ends of the first and secondelongate cables of the second anchor to create an attachment with one ofthe first and second ends of one of the first or second elongate cablesof the first, third, and fourth anchors, attaching each of the first andsecond ends of the first and second elongate cables of the third anchorto create an attachment with one of the first and second ends of one ofthe first or second elongate cables of the first, second, and fourthanchors, attaching each of the first and second ends of the first andsecond elongate cables of the fourth anchor to create an attachment withone of the first and second ends of one of the first or second elongatecables of the first, second, and third anchors, wherein each step ofattaching is accomplished by welding.
 2. The method of claim 1, whereinthe elongate cables are attached in the pattern of a quadrilateralhaving diagonal connections between vertices.
 3. The method of claim 1,wherein the elongate cables are attached in the pattern of afigure-eight having left and right generally vertically extendingsegments and diagonal connections between upper and lower end regions ofeach vertically extending segment.
 4. The method of claim 1, whereineach anchor further carries a second elongate cable having first andsecond ends that extend from each anchor.
 5. The method of claim 4,further comprising the steps of attaching each of the first and secondends of the second elongate cable of the first anchor to create anattachment with one of the first and second ends of the second elongatecable of the third and fourth anchors, attaching each of the first andsecond ends of the second elongate cable of the second anchor to createan attachment with one of the first and second ends of the secondelongate cable of the third and fourth anchors, wherein each step ofattaching is accomplished by welding.
 6. The method of claim 1, whereinthe method is used to prevent excessive movement across a spinalsegment.
 7. The method of claim 1, wherein the method is used forannulus and spinal ligament reconstruction.
 8. The method of claim 7further comprising the step of removing at least a portion of theannulus fibrosis between a first vertebra and a second vertebra.
 9. Themethod of claim 8, further comprising the step of inserting a total discreplacement device between a first vertebra and a second vertebra. 10.The method of claim 1, further comprising the step of removing at leasta portion of the nucleus within the annulus fibrosis between a firstvertebra and a second vertebra.
 11. The method of claim 1, furthercomprising the step of replacing at least a portion of the nucleuswithin the annulus fibrosis between a first vertebra and a secondvertebra.
 12. The method of claim 1, wherein the method is used across anatural disc adjacent to a fusion construct so as to protect theadjacent natural disc.
 13. The method of claim 1, wherein the method isused to treat any one or more of a natural undamaged disc, naturalinjured disc, a disc having a nucleus replacements, a damaged ordeformed vertebrae, damaged or deformed facets joints, and other spinalinjuries such as fractures, subluxations, or dislocations.
 14. Themethod of claim 1, further comprising the step of placing a mesh patchbetween the elongate cables and the annulus fibrosis.
 15. The method ofclaim 1, further comprising the step of placing an anti-adhesive patchcovering over the elongate cables.
 16. A method for attaching anintradiscal device between first and second vertebra, comprising thesteps of: providing a first anchor that carries an elongate cable havingfirst and second ends that extend from the anchor; attaching the anchorto one of a first vertebral endplate or a second vertebral endplate;passing one or more of the first and second ends of the elongate cablethrough a portion of the intradiscal device; inserting an intradiscaldevice between the first and second vertebra; and attaching the firstand second ends of the elongate cable by welding to secure theintradiscal device between the first and second vertebra.
 17. The methodof claim 16, wherein the intradiscal device is selected from a groupconsisting of: a cage, a bone graft, a fusion device, a motionpreserving device or a nucleus replacement device.
 18. The method ofclaim 16, wherein the step of passing one or more of the first andsecond ends of the elongate cable through a portion of the intradiscaldevice is performed after the step of inserting an intradiscal devicebetween the first and second vertebra.
 19. The method of claim 16,wherein said anchor is attached to a first vertebral endplate furthercomprising: providing a second anchor that carries a second elongatecable having first and second ends that extend from the second anchor;attaching the second anchor to a second vertebral endplate adjacent tosaid first vertebral endplate passing one or more of the first andsecond ends of the second elongate cable of the second anchor through aportion of the intradiscal device; and attaching the first and secondends of the second elongate cable by welding to secure the intradiscaldevice between the first and second vertebra
 20. The method of claim 19,further comprising applying tension to said first and second elongatecables.
 21. The method of claim 20, further comprising placing ananti-adhesion patch between the elongate cables and the intradiscaldevice.